systrace/catapult/third_party/polymer/components/iron-pages/iron-pages.html

<!--
@license
Copyright (c) 2015 The Polymer Project Authors. All rights reserved.
This code may only be used under the BSD style license found at http://polymer.github.io/LICENSE.txt
The complete set of authors may be found at http://polymer.github.io/AUTHORS.txt
The complete set of contributors may be found at http://polymer.github.io/CONTRIBUTORS.txt
Code distributed by Google as part of the polymer project is also
subject to an additional IP rights grant found at http://polymer.github.io/PATENTS.txt
-->

<link rel="import" href="../polymer/polymer.html">
<link rel="import" href="../iron-resizable-behavior/iron-resizable-behavior.html">
<link rel="import" href="../iron-selector/iron-selectable.html">

<!--
`iron-pages` is used to select one of its children to show. One use is to cycle through a list of
children "pages".

Example:

    <iron-pages selected="0">
      <div>One</div>
      <div>Two</div>
      <div>Three</div>
    </iron-pages>

    <script>
      document.addEventListener('click', function(e) {
        var pages = document.querySelector('iron-pages');
        pages.selectNext();
      });
    </script>

@group Iron Elements
@hero hero.svg
@demo demo/index.html
-->

<dom-module id="iron-pages">

  <template>
    <style>
      :host {
        display: block;
      }

      :host > ::content > :not(.iron-selected) {
        display: none !important;
      }
    </style>

    <content></content>
  </template>

  <script>
    Polymer({

      is: 'iron-pages',

      behaviors: [
        Polymer.IronResizableBehavior,
        Polymer.IronSelectableBehavior
      ],

      properties: {

        // as the selected page is the only one visible, activateEvent
        // is both non-sensical and problematic; e.g. in cases where a user
        // handler attempts to change the page and the activateEvent
        // handler immediately changes it back
        activateEvent: {
          type: String,
          value: null
        }

      },

      observers: [
        '_selectedPageChanged(selected)'
      ],

      _selectedPageChanged: function(selected, old) {
        this.async(this.notifyResize);
      }
    });

  </script>
</dom-module>